'59 Plymouth Forum

I put new shoes and wheel cylinders on rear due to a leaking cylinder,now can't get brakes on rear only. Could it be possible it's the proportening valve,
I have replaced single master cylinder with double cylinder assy from 1969 plymouth?

I never done A single to dual conversion but sounds like A proportion problem. If it was single I would suggest the shoes need adjusted more,as they are not self adjusted but need to do it manual (just till it kisses the drum) if you crack open A rear bleeder does air/fluid squirt out when pressing the pedal? Mark

Yes get fluid and air, when applying pedal front have brakes rear have none you can turn the drum shoes do not apply.

Instead of asking several questions here is a diagram i found for you i hope this helps

Car still has 4 wheel drum brakes could I take the proportion valve out and still work like single master cylinder?

Master cylinder could be defective, only creating pressure at the one port. Very common problem.

---John

thanks John, will try new master,do you know if the proportion will work in that system? I have that system on my 1967 dodge trk. that was a single master cyl and it has been working for several years.

Proportioning valves are generally used in disc front, drum rear systems to avoid having the front brakes lock up before the rears. Probably not necessary in your case.

---John

Thanks John

Better but not perfect I gutted the proportion valve that helped, think will put back single system.